As Washington focuses on what Vice President Joseph R. Biden Jr. will propose next week to curb gun violence, gun and ammunition sales are spiking in the rest of the country as people rush to expand their arsenals in advance of any restrictions that might be imposed.

People were crowded five deep at the tiny counter of a gun shop near Atlanta, where a pastor from Knoxville, Tenn., was among the customers who showed up in person after the store’s Web site halted sales because of low inventory. Emptying gun cases and bare shelves gave a picked-over feel to gun stores in many states. High-capacity magazines, which some state and federal officials want to ban or restrict, were selling briskly across the country: one Iowa dealer said that 30-round magazines were fetching five times what they sold for just weeks ago.

Gun dealers and buyers alike said that the rapid growth in gun sales — which began climbing significantly after President Obama’s re-election and soared after the Dec. 14 shooting at a school in Newtown, Conn., prompted him to call for new gun laws — shows little sign of abating.

December set a record for the criminal background checks performed before many gun purchases, a strong indication of a big increase in sales, according to an analysis of federal data by the National Shooting Sports Foundation, a gun industry trade group. Adjusting the federal data to try to weed out background checks that were unrelated to firearms sales, the group reported that 2.2 million background checks were performed last month, an increase of 58.6 percent over the same period in 2011. Some gun dealers said in interviews that they had never seen such demand.

Athena Gun Club’s showroom looks more like a high-end clothing store than a place to buy and shoot guns.

That’s why the business has become a favorite spot for seasoned gun owners as well as first-time buyers.

Now that gun control is at the top of President Barack Obama’s domestic agenda, more people are coming to businesses like this one, apparently thinking a ban on assault weapons and high-capacity ammunition magazines is just around the corner.